From 1daaf4485ff036ab56bfb617ec6a4877ebeb864f Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Mon, 16 Jun 2014 13:37:34 -0700
Subject: [PATCH] Refactor item set transition functions

---
 .../build_tables/item_set_transitions_spec.cc |  2 --
 spec/compiler/compiler_specs.cc               |  2 +-
 .../build_tables/build_parse_table.cc         |  1 -
 .../build_tables/item_set_transitions.cc      | 33 ++++++-------------
 .../build_tables/item_set_transitions.h       |  8 ++---
 5 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/spec/compiler/build_tables/item_set_transitions_spec.cc b/spec/compiler/build_tables/item_set_transitions_spec.cc
index a6262ef1..95c33414 100644
--- a/spec/compiler/build_tables/item_set_transitions_spec.cc
+++ b/spec/compiler/build_tables/item_set_transitions_spec.cc
@@ -40,8 +40,6 @@ describe("syntactic item set transitions", [&]() {
             { ParseItem(Symbol(0), seq({ i_token(22), i_sym(1) }), 3), { Symbol(23, SymbolOptionToken) } },
         });
 
-        SymTransitions sym_transitions;
-
         AssertThat(sym_transitions(set1, grammar), Equals(map<Symbol, ParseItemSet>({
             { Symbol(22, SymbolOptionToken), ParseItemSet({
                 { ParseItem(Symbol(0), i_sym(1), 4), { Symbol(23, SymbolOptionToken) } },
diff --git a/spec/compiler/compiler_specs.cc b/spec/compiler/compiler_specs.cc
index 2fdde15a..b971db39 100644
--- a/spec/compiler/compiler_specs.cc
+++ b/spec/compiler/compiler_specs.cc
@@ -5,7 +5,7 @@ int main(int argc, char *argv[]) {
         "",
         "--no-color",
         "--only="
-        ""
+        "compiles the javascript"
     };
     return bandit::run(4, const_cast<char **>(args));
 }
diff --git a/src/compiler/build_tables/build_parse_table.cc b/src/compiler/build_tables/build_parse_table.cc
index 90faf0a1..c2605bea 100644
--- a/src/compiler/build_tables/build_parse_table.cc
+++ b/src/compiler/build_tables/build_parse_table.cc
@@ -26,7 +26,6 @@ namespace tree_sitter {
             const PreparedGrammar grammar;
             ParseConflictManager conflict_manager;
             unordered_map<const ParseItemSet, ParseStateId> parse_state_ids;
-            SymTransitions sym_transitions;
             ParseTable parse_table;
 
             ParseStateId add_parse_state(const ParseItemSet &item_set) {
diff --git a/src/compiler/build_tables/item_set_transitions.cc b/src/compiler/build_tables/item_set_transitions.cc
index 6c44a23a..acdf5cc2 100644
--- a/src/compiler/build_tables/item_set_transitions.cc
+++ b/src/compiler/build_tables/item_set_transitions.cc
@@ -13,28 +13,20 @@ namespace tree_sitter {
 
     namespace build_tables {
         map<Symbol, ParseItemSet>
-        SymTransitions::operator()(const ParseItemSet &item_set, const PreparedGrammar &grammar) {
+        sym_transitions(const ParseItemSet &item_set, const PreparedGrammar &grammar) {
             map<Symbol, ParseItemSet> result;
-
             for (const auto &pair : item_set) {
                 const ParseItem &item = pair.first;
                 const set<Symbol> &lookahead_symbols = pair.second;
-                map<Symbol, ParseItemSet> result_for_item;
                 for (auto &transition : sym_transitions(item.rule)) {
                     ParseItem new_item(item.lhs, transition.second, item.consumed_symbol_count + 1);
-                    result_for_item.insert({
-                        transition.first,
-                        item_set_closure(new_item, lookahead_symbols, grammar)
-                    });
+                    merge_sym_transitions<ParseItemSet>(&result, {{ transition.first, item_set_closure(new_item, lookahead_symbols, grammar) }},
+                                                        [](ParseItemSet *left, const ParseItemSet *right) {
+                                                            for (auto &pair : *right)
+                                                                left->operator[](pair.first).insert(pair.second.begin(), pair.second.end());
+                                                        });
                 }
-                
-                merge_sym_transitions<ParseItemSet>(&result, result_for_item,
-                                                    [](ParseItemSet *left, const ParseItemSet *right) {
-                                                        for (auto &pair : *right)
-                                                            left->operator[](pair.first).insert(pair.second.begin(), pair.second.end());
-                                                    });
             }
-            
             return result;
         }
 
@@ -42,18 +34,13 @@ namespace tree_sitter {
         char_transitions(const LexItemSet &item_set, const PreparedGrammar &grammar) {
             map<CharacterSet, LexItemSet> result;
             for (const LexItem &item : item_set) {
-                map<CharacterSet, LexItemSet> item_transitions;
                 for (auto &transition : char_transitions(item.rule)) {
                     LexItem next_item(item.lhs, transition.second);
-                    item_transitions.insert({
-                        transition.first,
-                        LexItemSet({ next_item })
-                    });
+                    merge_char_transitions<LexItemSet>(&result, {{ transition.first, LexItemSet({ next_item }) }},
+                                                       [](LexItemSet *left, const LexItemSet *right) {
+                                                           left->insert(right->begin(), right->end());
+                                                       });
                 }
-                merge_char_transitions<LexItemSet>(&result, item_transitions,
-                                                   [](LexItemSet *left, const LexItemSet *right) {
-                                                       left->insert(right->begin(), right->end());
-                                                   });
             }
             return result;
         }
diff --git a/src/compiler/build_tables/item_set_transitions.h b/src/compiler/build_tables/item_set_transitions.h
index 39354178..6cb62ebc 100644
--- a/src/compiler/build_tables/item_set_transitions.h
+++ b/src/compiler/build_tables/item_set_transitions.h
@@ -13,12 +13,8 @@ namespace tree_sitter {
     }
 
     namespace build_tables {
-        class SymTransitions {
-        public:
-            std::map<rules::Symbol, ParseItemSet>
-            operator()(const ParseItemSet &item_set, const PreparedGrammar &grammar);
-            std::map<rules::rule_ptr, std::map<rules::Symbol, ParseItemSet>> transitions_cache;
-        };
+        std::map<rules::Symbol, ParseItemSet>
+        sym_transitions(const ParseItemSet &item_set, const PreparedGrammar &grammar);
 
         std::map<rules::CharacterSet, LexItemSet>
         char_transitions(const LexItemSet &item_set, const PreparedGrammar &grammar);